A consist includes one or more locomotives that are coupled together to produce motive power for a train of rail vehicles. The locomotives each include one or more engines, which combust fuel to produce mechanical power. The engine(s) of each locomotive can be supplied with liquid fuel (e.g., diesel fuel) from an onboard tank, gaseous fuel (e.g., natural gas) from a tender car, or a blend of the liquid and gaseous fuels. The mechanical power produced by the combustion process is directed through a generator and used to generate electricity. The electricity is then routed to traction motors of the locomotives, thereby generating torque that propels the train. The locomotives can be connected together at the front of the train, or separated and located at different positions along the train. For example, the consist can be positioned at the front, middle, or end of the train. In some instances, more than one consist can be included within a single train. In some consists, the locomotives include computer systems for coordinating operations of the locomotives.
Because the locomotives of a consist must cooperate to propel the train, communication between the locomotives can be important. Historically, this communication has been facilitated through the use of an MU (Multi-Unit) cable that extends along the length of the consist. An MU cable is comprised of many different wires, each capable of carrying a discrete signal used to regulate a different aspect of consist operation. For example, a lead locomotive generates current within a particular one of the wires to indicate a power level setting requested by the train operator. When this wire is energized, the engines of all trailing locomotives are caused to operate at a specific throttle level. In another example, when one locomotive experiences a fault condition, another of the wires is energized to alert the other locomotives of the condition's existence.
In some consists, the locomotives communicate via the computer systems on an Ethernet network formed over the MU cables or over other intra-consist electrical cables. With this configuration, network data can be transmitted from the computer system in the lead locomotive to the computer systems in the trail locomotives, and vice-versa. The network data includes data that is packaged as data packets and uniquely addressed to particular computer systems or particular components connected with the computer systems. The network data can be, for example, vehicle sensor data indicative of vehicle health, commodity condition data, temperature data, weight data, and security data. The network data is transmitted orthogonal to conventional non-network (i.e., command) data that is already being transmitted on the MU cable.
Although functional with newer locomotives having digital components, the computer systems may not function well with older locomotives. In particular, some or all of the signals generated by existing sensors and components of the older locomotives may be analog signals, and the computer systems may be capable of receiving, interpreting, recording, and/or transmitting only digital signals. In addition, some existing systems and/or components of older locomotives may not be monitored at all and, accordingly, may be incompatible with modern computer systems.
One attempt to improve communication within a train is described in U.S. Pat. No. 7,869,908 of Walker that issued on Jan. 11, 2011 (“the '908 patent”). Specifically, the '908 patent describes a computer-implemented system for a locomotive. The system includes a digital microprocessor having an expansion area with an analog-to-digital (A/D) converter, The A/D converter receives and stores discrete electronic signals from analog sources on the locomotive, such as from an onboard sensor monitoring an air manifold pressure. This allows the microprocessor to determine a state or condition of the analog sources. Data received via the expansion area is logged into a database and used for troubleshooting or analysis.
While the system disclosed in the '908 patent may avoid some of the disadvantages of an all-digital network, it may still be problematic. In particular, the system may still not account for older locomotives having unmonitored systems or components.
The disclosed communication network and expansion module are directed to overcoming one or more of the problems set forth above.